1. Field of the Invention
The present invention relates to a single lens reflex camera, and more precisely it relates to electrical contact mechanism in a single lens reflex camera for transmitting and receiving an electrical power and/ or electrical signals between a camera body and an interchangeable lens.
2. Description of Related Art
In a known single lens reflex cameras, an electrical power and /or electrical signals are transmitted to and camera body, respectively and interchangeable lens to an interchangeable lens or a camera body. To transmit and receive the electrical power and the electrical signals in the form of electric current, it is necessary to provide electrical contacts which are connected on the camera body and the interchangeable lens, respectively, when the interchangeable lens is mounted to the camera body. Usually, the electrical signals which are transmitted from the interchangeable lens to the camera body include information, such as open F-number, focal length data, etc., peculiar to the associated interchangeable lens, which are stored in a ROM or CPU incorporated in the interchangeable lens. However, in a recent interchangeable lens with a powered zoom or a powered diaphragm, there is more information to be transmitted between the camera body and the interchangeable lens. It is also necessary to supply the electrical power to the interchangeable lens from the camera body.
The electrical contacts are usually provided on a lens mount and a body mount, or the vicinity thereof. However, in the vicinity of the lens mount and body mount, there are usually locking and unlocking mechanisms of the interchangeable lens and driving and driven shafts for auto-focusing and power-zooming operations, etc., Hence, there is insufficient space for providing a number of electrical contacts. Consequently, there is required a complicated arrangement of the electrical contacts. Also, it is almost impossible to accommodate an increased number of electrical contacts.